Beryllium is a toxic metal that is used in a wide variety of industries including electronics, aerospace, and the DOE complex. Exposure to beryllium containing particles can lead to a lung disease called chronic beryllium disease (CBD). CBD involves an uncontrolled immune response in the lungs that can lead to deterioration in breathing capacity and ultimately death. It is clear that even in processes where beryllium dust has been controlled to very low levels cases of disease still persist. In fact, there have been cases of CBD reported in people that have had no obvious direct contact with beryllium operations. Despite the fact that very low exposure levels can lead to CBD, the onset of disease can take decades. Over 150 people from one facility alone have been diagnosed with CBD.
Recent new regulations dictate a permissible exposure limit of 2.0 μg/m3, a housekeeping level of 3 μg/100 cm2 on a surface, and a release level for materials of 0.2 μg/100 cm2. Currently, thousands of swipes are analyzed annually for beryllium. In addition OSHA has detected airborne levels of beryllium at numerous companies within the United States. The present technique is to swipe an area with a filter paper or pull a known volume of air through a filter paper, do a microwave digestion with acid, and then analyze by inductively coupled plasma atomic emission. This process can take two days or more and is not readily fieldable. The inductively coupled plasma (ICP) atomic emission technique also requires the entire sample in order to meet the detection levels so that a sample that came up positive for beryllium can never be checked or verified with a second run.
Although there are several reports of being able to detect beryllium with a fluorescent indicator, there are no fluorimetric beryllium detection methods that have been approved for use by governmental concerns. Three key elements to a useful detection system have been missing previously. First, the detection system must be capable of dissolving beryllium oxide and beryllium metal. Second, the detection system must work in the presence of other metals and fluoride. Third, the detection system must be easy to use and preferably offer the ability to be field portable. Most fluorescent indicators reported in literature do not tolerate the presence of fluoride, which is critical if a fluoride-based medium is used to dissolve the beryllium. The few reports of fluorescent indicators that can tolerate fluoride, have used complicated procedures involving heating with acid for dissolution and a titration process to obtain the final pH that require long periods of time and prohibit use in the field.
The extensive chemistry required in previous fluorescent systems and the interferences from other metals has limited their use, and to date there is no simple approach to beryllium detection by fluorescence. A quick, simple approach has now been developed for the detection and quantification of beryllium.
It is an object of the present invention to provide a quantitative method of determining beryllium or a compound thereof (including beryllium oxide) in a sample, which has a fast turnaround time and can be made to be readily field portable.
Another object of the present invention is to provide a quantitative method of determining beryllium or a compound thereof in a sample, which can tolerate a wide variety of metals, including iron, aluminum, and/or uranium at high levels as well as high concentrations of fluoride without affecting the detection of beryllium or a compound thereof.
Another object of this invention is to provide a synthetic route to making 10-hydroxybenzo[h]quinoline-7-sulfonate, the preferred indicator used to detect beryllium.